Fig. 2: Single-channel characterization and functional stability of DpPorA DE.

a DpPorA DE peptide sequence, monomer structure, and CD spectra of DpPorA DE (dark green) and LpPorA DE (light green) in 10 mM phosphate buffer with 1% DDM. b Electrical recording of multiple channel insertion at +50 mV with corresponding all-point current amplitude histogram. c Single-channel insertion at +150 mV with unitary conductance histogram of n = 61 insertion events, as inset. d The reverse potential was obtained from the I–V curve of a single DpPorA DE pore in an asymmetric buffer (0.15 M KCl at cis and 1 M KCl at trans) for charge selectivity. Error bars represent 10% standard error mean between 4 independent experiments. e Overlapping stable current trace of DpPorA DE and LpPorA DE at +50 mV. f Stacked mean unitary conductance histogram of DpPorA DE (dark green) and LpPorA DE (light green), obtained by fitting the distribution to Gaussian (number of insertion events, n = 61 and n = 26 for DpPorA DE and LpPorA DE, respectively). g Interaction of 100 µM E9 with DpPorA DE on the cis side at +40 mV. h Interaction of 500 µM PEG 200-E9 with DpPorA DE on the cis side at +40 mV. Insets show corresponding dissociation dwell time (τ_off) histogram fitted with a monoexponential probability function and recording at an expanded time scale. i Interaction of 25 nM alpha-synuclein (αS) with DpPorA DE on the cis side at +40 mV. Insets show corresponding current amplitude histogram and recording at an expanded time scale. j Competitive interaction of 100 µM E9 (brown), 500 µM PEG 200-E9 (orange), and 25 nM alpha-synuclein (αS) (magenta) with DpPorA DE (cis side) at +40 mV. The current signals (b, c, e) were digitally filtered at 2 kHz. The current signals (g–j) were filtered at 10 kHz and sampled at 50 kHz. Electrolyte: 1 M KCl, 10 mM HEPES, pH 7.4.